A third of all humans carry the parasite that causes toxoplasmosis — a disease commonly associated with cats, HIV-AIDS patients and pregnant women — with scientists long believing healthy immune systems control the parasite and prevent the disease from emerging.

Researchers at the University of California, Merced, have completed a comprehensive map of the genetic makeup of melanoma, the deadliest form of skin cancer. By comparing the genomes of more than 300 melanomas, the researchers were able to identify mutational hotspots that give rise to cancer.